Another possibility is that the Earth initially had a much bigger crust, full of silicon that was then blasted away through impacts with meteorites.
Since gravity is related to mass, the shifting of a big chunk of crust at the quake's epicenter will change the gravitational equation at that location.
Meanwhile, faster objects may have potentially slammed into Vesta so hard they melted the big asteroid's crust, which could have also created the dark spots.
These guys clearly know what they're doing - the crust is big, but not offensively so.
Empanadillas with a flaky, light crust — and big enough to fit in two hands — are piled high by the front counter, next to a tray with whole roasted chickens.
Richardson says that the study team has identified a transition zone between the upper crust, where big earthquakes go off on the rare occasions when there is slip, and the deep, soft crust, where the fault grinds along more quietly, through the slippage of nearly continuous little tremors.
"The biggest fear is the crust.
Quammen describes Charlie as "… a smallish man with a dangerous twinkle, famed throughout the profession for his depth of knowledge, his caustic humor, his disdain for pomposity, his brusque manner, and (if you happen to get past those crusts), his big, affable heart".
My one big change was in the crust.
Even better was a pear and apple tart, with caramelized puff pastry crust and a big scoop of vanilla ice cream.
